Sysfs is about to get a new interface which is independent from thedriver model and kobject. Create include sysfs-kobject.h and move allkobject based interface into it. Also, create fs/sysfs/kobject.cwhich is currently empty but will host compatibility interfacefunctions based on the new interface.

sysfs-kobject.h is automatically included from sysfs.h forcompatibility for now.